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Adaptive Displaced Phase Center Antenna Pulse Canceller

When to Use the Adaptive DPCA Pulse Canceller

Consider an airborne radar system that needs to suppress clutter
returns and possibly jammer interference. Under any of the following
conditions, you might choose an adaptive DPCA (ADPCA) pulse canceller
for suppressing these effects.

Jamming and other interference effects are substantial.
The DPCA pulse canceller is susceptible to interference because the
DPCA pulse canceller does not use the received data.

The sample matrix inversion (SMI) algorithm is inapplicable
because of computational expense or a rapidly changing environment.

The phased.ADPCAPulseCanceller object implements
an ADPCA pulse canceller. This pulse canceller uses the data received
from two consecutive pulses to estimate the space-time interference
covariance matrix. In particular, the object lets you specify:

The number of training cells. The algorithm uses training
cells to estimate the interference. In general, a larger number of
training cells leads to a better estimate of interference.

The number of guard cells close to the target cells.
The algorithm recognizes guard cells to prevent target returns from
contaminating the estimate of the interference.

Adaptive DPCA Pulse Canceller

This example implements an adaptive DPCA pulse canceller for clutter and interference rejection. The scenario is identical to the one in DPCA Pulse Canceller to Reject Clutter except that a stationary broadband barrage jammer is added at (3.5e3,1e3,0). The jammer has an effective radiated power of 1 kW.

To repeat the scenario for convenience, the airborne radar platform is a six-element ULA operating at 4 GHz. The array elements are spaced at one-half the wavelength of the 4 GHz carrier frequency. The radar emits ten rectangular pulses of two μs duration with a PRF of 5 kHz. The platform is moving along the array axis with a speed equal to one-half the product of the element spacing and the PRF. ADPCA pulse cancellation is applicable because where

indicates the speed of the platform

represents the pulse repetition interva

indicates the interelement spacing of the array

The target has a nonfluctuating RCS of 1 square meter and is moving with a constant velocity vector of (15,15,0).

Note: This example runs only in R2016b or later. If you are using an earlier release, replace each call to the function with the equivalent step syntax. For example, replace myObject(x) with step(myObject,x).

Propagate the ten rectangular pulses to the target and back and collect the responses at the array. Compute clutter echoes using the constant gamma model with a gamma value corresponding to wooded terrain. Also, propagate the jamming signal from the jammer location to the airborne ULA.